Art Deco paste dress clip by Knoll and Pregizer, in 935 Silver, also marked DRGM. This small treasure is dazzling, its paste stones imitating diamonds and a sapphire. The condition is excellent with all original stones and no chips, and a secure clip mechanism. Knoll and Pregizer of Pforzheim, Germany, in business between 1887 and 1975, produced exquisite jewels that are highly collectible. This dress clip is a superb example of their work. It measures 1" by 3/4" and is marked 935 (for silver content above sterling), conjoined KP in a lozenge, and DRGM (the German patent mark used between 1891- WWII).
Please have a look at the Robin Deutsch Collection on Image Event. Robin is the expert on K&P and her article and photos are illuminating.